The biogenesis of muscle glycogen: regulation of the activity of the autocatalytic primer protein.
Glycogen synthesis in rabbit muscle is initiated by an autocatalytic, self-glucosylating protein (SGP). This creates a maltosaccharide primer on itself that in turn primes glycogen synthesis. Here we describe the powerful allosteric inhibition of autocatalysis by ATP and ADP, sufficient, at the physiological concentration of ATP in muscle, to inhibit autocatalysis. We also examined inhibition of self-glucosylation by analogues of the substrate UDPglucose. One of them, UDPxylose, acts as an alternative substrate and serves to block glucosylation. An improved purification procedure for the SGP is also described.
Lomako
J
J
Department of Biochemistry and Molecular Biology, University of Miami School of Medicine, FL 33101.
Lomako
W M
WM
Whelan
W J
WJ
D000494:Allosteric Regulation / Q000502:physiology; D000818:Animals; D002384:Catalysis; D006003:Glycogen / Q000096:biosynthesis*; D009124:Muscle Proteins / Q000302:isolation & purification / Q000502:physiology*; D009132:Muscles / Q000378:metabolism*; D009702:Nucleoside Diphosphate Sugars / Q000494:pharmacology; D009711:Nucleotides / Q000502:physiology; D011817:Rabbits
D009124:Muscle Proteins; D009702:Nucleoside Diphosphate Sugars; D009711:Nucleotides; D006003:Glycogen